The purpose of this project will be to develop a general-purpose instrument for measuring fluorescence lifetimes on and inside the eye. This instrument will take advantage of fluorescence lifetime probes designed for microscopy and analytical chemistry to measure electrolytes, pH, glucose, oxygen and more in and on live eyes in animals and eventually humans. This will have obvious applications in eye research and may eventually have applications in disease diagnosis. During Phase I, we will demonstrate feasibility of this technique in the eye, as well as characterize the fluorescence lifetime of ocular autofluorescence. This characterization will be important to planning future projects since this autofluorescence generally will be "noise" to exogenous fluorescent sensors. Of course, in other research applications ocular autofluorescence could also be the target. Lens autofluorescence has been shown to be an indicator of diabetes, corneal autofluorescence of diabetic eye disease and fluorescent retinal lipofuscins have been implicated in the pathogenesis of Age Relate Macular Degeneration (AMD). Our overall goal will be to produce a standardized instrument and to develop protocols for using fluorescent lifetime sensors for making measurements in or on the eye. A critical goal will be standardization and calibration control, so that results made on different machines will be comparable. In addition, we will design this instrument with enough flexibility so that we can add capabilities as new fluorescence lifetime probes are developed, and our customers can develop techniques of their own.